hi i have a vn v8 that overheated and stalled. i got it to start the next day and it started really ruff and had bit problem with idle. i checked timing and changed it back to base. start is still bit ruff but find's a nice idle quickly. however it rev ohkish but as soon as u let go of the revs it drops and almost stalls. wat are some thing i should check first before going all out and pulling the manifold off to see it leaking into the cylinder